Angewandte Chemie International Edition, 04 October, 2019，DOI：https://doi.org/10.1002/anie.201909203
S‐Click Reaction for Isotropic Orientation of Oxidases on Electrodes to Promote Electron Transfer at Low Potentials
Dr. Lin Xia Dr. Ming‐Jie Han Lu Zhou Dr. Aiping Huang Zhaoya Yang Tianyuan Wang Dr. Fahui Li Dr. Lu Yu Prof. Changlin Tian Zhongsheng Zang Prof. Qing‐Zheng Yang Prof. Chenli Liu Dr. Wenxu Hong Prof. Yi Lu Prof. Lital Alfonta Prof. Jiangyun Wan
Electrochemical sensors are essential for point‐of‐care testing (POCT) and wearable sensing devices. Establishing an efficient electron transfer route between redox enzymes and electrodes is key for converting enzyme‐catalyzed reactions into electrochemical signals, and for the development of robust, sensitive, and selective biosensors. We demonstrate that the site‐specific incorporation of a novel synthetic amino acid (2‐amino‐3‐(4‐mercaptophenyl)propanoic acid) into redox enzymes, followed by an S‐click reaction to wire the enzyme to the electrode, facilitates electron transfer. The fabricated biosensor demonstrated real‐time and selective monitoring of tryptophan (Trp) in blood and sweat samples, with a linear range of 0.02–0.8？mm. Further developments along this route may result in dramatic expansion of portable electrochemical sensors for diverse health‐determination molecules.